Snowmobiles are powered by engines that need to be cooled. In some snowmobiles, a coolant is circulated around and through the engine thereby absorbing the heat generated by the engine. When the hot coolant leaves the engine, it needs to be cooled before being returned to the engine. To do so, the coolant is circulated through one or more heat exchanger assemblies.
FIG. 1 illustrates an exemplary implementation of a prior art arrangement of heat exchanger assemblies for a snowmobile. The arrangement includes a front heat exchanger assembly 1000 and a heat exchanger assembly 1002.
The front heat exchanger assembly 1000 has a body 1004 defining an internal volume, an outlet pipe 1006 and an inlet pipe 1008. The pipes 1006, 1008 are welded to the body 1004. Fins 1010 are formed on the back of the body 1004. The front heat exchanger 1000 defines in part a front of a tunnel of the snowmobile.
The heat exchanger assembly 1002 defines in part a top of the tunnel of the snowmobile. The heat exchanger assembly 1002 has a body 1012, and inlet pipe 1014, an outlet pipe 1016, and a connector 1018. Fins 1020 are formed on the bottom of the body 1012. The body 1012 is formed by being extruded. The extrusion process forms two passages 1022, 1024. The connector 1018, also formed by extrusion, is connected to the back of the two passages 1022, 1024 to fluidly connect the two together thereby forming a single passage. The passages 1022, 1024 are capped at their front ends. The inlet pipe 1014 is welded at a front of the passage 1022 and the outlet pipe 1016 is welded at a front of the passage 1024.
A pipe (not shown) connects the inlet pipe 1014 of the heat exchanger assembly 1002 to the engine to receive hot coolant from the engine. Another pipe (not shown) connects the outlet pipe 1016 of the heat exchange assembly 1002 to the inlet pipe 1008 of the heat exchanger assembly 1000 to allow coolant to flow from the heat exchanger assembly 1002 to the heat exchanger assembly 1000. Another pipe (not shown) connects the outlet pipe 1006 of the heat exchanger assembly 1000 to the engine to return cooled coolant to the engine.
During operation of the snowmobile, coolant flows from the engine to the heat exchanger assembly 1002. In the heat exchanger assembly 1002, coolant first flows through the passage 1022, then through the connector 1018, and then through the passage 1024. From the passage 1024 the coolant flows to the heat exchanger assembly 1000. From the heat exchanger assembly 1000, the coolant is returned to the engine.
The coolant in the heat exchanger assemblies 1000, 1002 is cooled by a combination of air flowing along the surfaces of the heat exchanger assemblies 1000, 1002 and snow being projected on the surfaces of the heat exchanger assemblies 1000, 1002 by the drive track of the snowmobile.
Although the arrangement of the heat exchanger assemblies 1000, 1002 effectively cools the coolant of the engine, it has some disadvantages.
First, the heat exchanger assemblies 1000, 1002 are separate from each other, which increases the complexity of their assembly to the snowmobile.
Also, since the body 1012 of the heat exchanger assembly 1002 is extruded, the passages 1022, 1024 need to have a constant cross-sectional area along their lengths. As such, they are not shaped to take mostly advantage of the regions where more cooling can occur such as where the snow is being sprayed by the drive track. Therefore, the overall internal volume of the heat exchanger assembly 1002 is greater than necessary, which results in a larger volume of coolant being provided in the cooling system. Therefore, the snowmobile is heavier than necessary due to the coolant.
Finally, also due to the manner in which the bodies 1004, 1012 of the heat exchanger assemblies 1000, 1002 are manufactured, the pipes 1006, 1008, 1014 and 1016 are welded generally perpendicular to the surfaces on which they are welded. This is because placing the pipes 1006, 1008, 1014 and 1016 at an angle to their respective connection surfaces would make welding difficult. As a result, the pipes 1006, 1008, 1014 and 1016 take more room by being perpendicular then if they were disposed at another angle.
Accordingly, it would be desirable to have a heat exchanger assembly that can replace two heat exchanger assemblies such as the ones described above.
It would also be desirable to have a heat exchanger assembly that takes advantage of areas where more cooling can occur.
It would also be desirable to have a heat exchanger assembly that facilitates the welding of at least one of the inlet and outlet pipes at an angle to the surface to which it is being welded.